/*
 * The MIT License
 * 
 * Copyright (c) 2011 Takahiro Hashimoto
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package com.taobao.top.link.embedded.websocket.proxy;

import static com.taobao.top.link.embedded.websocket.exception.ErrorCode.E3032;

import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.ProxySelector;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.UnknownHostException;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.taobao.top.link.embedded.websocket.WebSocket;
import com.taobao.top.link.embedded.websocket.auth.Authenticator;
import com.taobao.top.link.embedded.websocket.auth.Credentials;
import com.taobao.top.link.embedded.websocket.auth.DefaultAuthenticator;
import com.taobao.top.link.embedded.websocket.exception.WebSocketException;
import com.taobao.top.link.embedded.websocket.handshake.ProxyHandshake;

/**
 * The Class Proxy.
 *
 * @author Takahiro Hashimoto
 */
public class Proxy {
  /** The log. */
  private static Logger     log        = Logger.getLogger(Proxy.class.getName());

  /** The auto detect. */
  private boolean           autoDetect = false;

  /** The proxy. */
  private InetSocketAddress proxy;

  /** The authenticator. */
  private Authenticator     authenticator;

  /** The credentials. */
  private Credentials       credentials;

  /**
   * Instantiates a new proxy.
   */
  public Proxy() {
    this.autoDetect = true;
    this.authenticator = null;
  }

  /**
   * Instantiates a new proxy.
   *
   * @param proxyAddress
   *          the proxy address
   */
  public Proxy(InetSocketAddress proxyAddress) {
    this.proxy = proxyAddress;
    this.authenticator = null;
  }

  /**
   * Instantiates a new proxy.
   *
   * @param username
   *          the username
   * @param password
   *          the password
   */
  public Proxy(String username, String password) {
    this.autoDetect = true;
    this.authenticator = new DefaultAuthenticator();
    this.credentials = new Credentials(username, password);
  }

  /**
   * Instantiates a new proxy.
   *
   * @param credentials
   *          the credentials
   * @param authenticator
   *          the authenticator
   */
  public Proxy(Credentials credentials, Authenticator authenticator) {
    this.autoDetect = true;
    this.credentials = credentials;
    this.authenticator = authenticator;
  }

  /**
   * Instantiates a new proxy.
   *
   * @param proxyAddress
   *          the proxy address
   * @param username
   *          the username
   * @param password
   *          the password
   */
  public Proxy(InetSocketAddress proxyAddress, String username, String password) {
    this.proxy = proxyAddress;
    this.authenticator = new DefaultAuthenticator();
    this.credentials = new Credentials(username, password);
  }

  /**
   * Instantiates a new proxy.
   *
   * @param proxyAddress
   *          the proxy address
   * @param credentials
   *          the credentials
   * @param authenticator
   *          the authenticator
   */
  public Proxy(InetSocketAddress proxyAddress, Credentials credentials, Authenticator authenticator) {
    this.proxy = proxyAddress;
    this.authenticator = authenticator;
    this.credentials = credentials;
  }

  /**
   * Find proxy.
   *
   * @param endpoint
   *          the endpoint
   * @return the inet socket address
   * @throws com.taobao.top.link.embedded.websocket.exception.WebSocketException
   *           the web socket exception
   */
  protected InetSocketAddress findProxy(InetSocketAddress endpoint) throws WebSocketException {
    try {
      System.setProperty("java.net.useSystemProxies", "true");
      URI proxyUri = new URI("http", null, endpoint.getHostName(), endpoint.getPort(), null, null, null);
      List<java.net.Proxy> proxyList = ProxySelector.getDefault().select(proxyUri);
      if (proxyList != null && proxyList.size() > 0 && !proxyList.get(0).type().equals(java.net.Proxy.Type.DIRECT)) {
        if (log.isLoggable(Level.FINER)) {
          int i = 1;
          for (java.net.Proxy p : proxyList) {
            log.finer("Proxy[" + i++ + "]" + p.toString());
          }
        }
        InetSocketAddress address = (InetSocketAddress) proxyList.get(0).address();
        try {
          // FIXME A proxy(ip address only) of the ProxySelector has
          // the Unresolved address.
          // so this code do resolve an ip address proxy
          address = new InetSocketAddress(InetAddress.getByName(address.getHostName()), address.getPort());
        } catch (UnknownHostException e) {
          e.printStackTrace();
        }
        return address;
      }
    } catch (URISyntaxException e) {
      throw new WebSocketException(E3032, e);
    }
    return null;
  }

  /**
   * Gets the proxy handshake.
   *
   * @param ws
   *          the ws
   * @return the proxy handshake
   * @throws WebSocketException
   *           the web socket exception
   */
  public ProxyHandshake getProxyHandshake(WebSocket ws) throws WebSocketException {
    InetSocketAddress proxy = null;
    if (this.autoDetect) {
      proxy = findProxy(ws.getEndpoint());
      if (proxy == null) {
        return null;
      }
    } else {
      proxy = this.proxy;
    }

    if (this.authenticator != null) {
      this.authenticator.init(ws, this.credentials);
    }

    ProxyHandshake proxyHandshake = new ProxyHandshake(proxy, ws.getEndpoint(), this.authenticator, ws);
    return proxyHandshake;
  }
}
